Oxygen enrichment of indoor human environments

ABSTRACT

This invention provides systems and methods of supplying oxygen-enriched air to an enclosed space or compartment. The systems and methods may distill oxygen from ambient air by a molecular sieve pressure cycle mechanism, such as a pressure swing absorption, may generate oxygen from water using electricity or may use oxygen enriched air produced by membrane filtration. The invention helps people improve their wellness, productivity and comfort, improve performance of mental and/or physical tasks, increase their alertness, quality of life and pleasure, reduce their drowsiness, and aid in curing and preventing disease by increasing the percentage of oxygen in the enclosed space to a beneficial and safe level.

FIELD OF THE INVENTION

This invention relates generally to systems and methods for supplyingoxygen enriched air to an enclosed space for prolonged or constant humanconsumption. The systems and methods may distill oxygen from ambient airby a molecular sieve pressure cycle mechanism, such as a pressure swingabsorption, may generate oxygen from water using electricity or may useoxygen enriched air produced by membrane filtration. The system mayinclude an oxygen battery, sensor and regulator for controlling andregulating the oxygen or oxygen-enriched air to maintain the oxygencontent of the air in the enclosed space within an optimum range.

BACKGROUND OF THE INVENTION

The most vital element on earth is oxygen. Without it, human life simplycould not exist. Oxygen is about 21% by volume (about 23% by weight) ofour natural atmosphere, regardless of climate, altitude and geography.It is believed that in the past, atmospheric oxygen levels were higher,perhaps significantly so, than today. The decrease in oxygen content ofambient air during the last couple of centuries may be a result ofreductions in plant life and/or increases in the use of fossil fuels,among other factors. Oxygen levels may have exceeded 35% in prehistorictimes.

There is little doubt that lower oxygen levels impair physical andmental function. In urban areas and enclosed spaces, oxygen levels canbe substantially lower than 21%. In high altitudes, relative oxygenconcentration is the same but all gases are rarefied, which isequivalent to lower oxygen levels.

The level of carbon dioxide (CO₂) in our blood triggers breathing, notthe amount of oxygen. Humans are not very good at compensating for lowor high oxygen levels by breathing more or less. The benefit of higheroxygen concentration is that getting more oxygen, at least some of thetime, is highly desirable. Medical treatment for intensive care and forvery sick patients routinely uses high purity oxygen.

Hyper baric oxygen treatment is a very common form of alternativemedicine believed by many to have broad health benefits ranging fromaging and aches to cancer and infectious diseases. Oxygen bars havecropped up that offer healthy patrons pure oxygen inhalation. There arebooks and groups espousing the therapeutic value of increased oxygenintake and its critical role in vast array of common ailments.

Oxygen separation is a well-established technology. Purified oxygen isthe third largest bulk chemical market. It is of critical importance inindustrial processes, medicine, research and development andaquaculture. In the future, purified oxygen could have dramatic positiveimpact on energy generation and reduction of air pollution.

Several technologies exist for separating oxygen from air. Onetechnology is Pressure Swing Adsorption (PSA) devices which are used forsmaller, on-site applications. This technology was originally developedin the 1950s-1960s. Another technology is cryogenic separation, which isoften used, in large industrial facilities.

New oxygen separation technologies are being developed. There aresignificant ongoing efforts in industry and academic research to findcheaper and more efficient ways to separate pure oxygen. Most of thesemethods are based on diffusion or filtering through new materials suchas ceramics, membranes, etc. All of these efforts target existingindustrial and medical applications. A particular important target ismaking it economically feasible to use enriched oxygen in burning fossilfuels.

SUMMARY OF THE INVENTION

The present invention includes an oxygen-enrichment system, the systemmay include oxygen distilled from ambient air using a molecular sievepressure cycle mechanism fed into the enclosed space, may include anelectrolyzing system for evolving gaseous oxygen from water and feedingthe oxygen into the enclosed space, may use oxygen from a storage tankor tanks adjoining the enclosed space, or may include a membrane systemto produce oxygen-enriched air which is fed into the enclosed space. Theinvention may include a sensor and regulator that detects the oxygencontent of the air in the enclosed space and controls the oxygen supplyto regulate the oxygen flow into the enclosed space. The system can beset to flow oxygen-enriched air into the enclosed space if the percentof oxygen in the enclosed space falls to or below a pre-selected valueand shut off the supply of oxygen-enriched air when the oxygen contentrises to a pre-selected value. The system may include a diluter toreduce the concentration of the oxygen that is supplied into theenclosed space.

The optimum percent of oxygen in the enclosed space for increasingalertness, improving productivity and comfort, reducing drowsiness, andincreasing overall well-being need be only a few percent above thepercent of oxygen in ambient air. It is believed that raising thepercent oxygen to a range of about 25-40% by volume can substantiallyincrease the alertness, productivity, comfort and overall well being ofpeople breathing the air. It is desirable to keep the oxygen content inthe enclosed space from exceeding approximately 40% by volume tominimize a possible risk of fire hazard or oxygen toxicity in theenclosed space.

This invention also provides a method for providing a small increase inthe oxygen content of air in enclosed spaces using the disclosedsystems. The invention provides a method that helps people increasetheir alertness, improve their productivity and comfort, reduce theirdrowsiness, improved metabolism and increase their overall well-beingand prevent disease.

The details of one or more embodiments of the invention are set forth inthe accompanying description below. Although any methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, the preferred methods andmaterials are now described. Other features, objects, and advantages ofthe invention will be apparent from the description. In thespecification and the appended claims, the singular forms also includethe plural unless the context clearly dictates otherwise. Unless definedotherwise, all technical and scientific terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich this invention belongs. All patents and publications cited in thisspecification are incorporated herein by reference.

DETAILED DESCRIPTION

In one embodiment, the present invention includes a system for producingand supplying oxygen-enriched air to an enclosed space or compartment.In preferred embodiments, the enclosed space includes, but is notlimited to a residence, room, house, apartment, building, theater,shopping center, hotel, office, industrial facility, commercialfacility, commercial venue, passenger car, truck, van, bus, tractor,ship, boat, submarine, aircraft, train or subway car. As used herein,the phrase “enclosed space” is used to mean any space that is not openor outdoors or any space which can be separated from the ambient air bypartition.

Molecular Sieve Pressure Cycle Mechanism

In a preferred embodiment, the oxygen producing system distills oxygenfrom ambient air by a molecular sieve pressure cycle mechanism todeliver oxygen-enriched air to an enclosed space. The system preferablyincludes an oxygen concentration sensor for measuring the oxygen contentin the enclosed space, a regulator for opening and closing a valve andfeeding oxygen into a conduit or pipe. The conduit or pipe is utilizedto flow oxygen to the enclosed space from the oxygen generator/producer.

The system enriches the oxygen content of the air in an enclosed spaceto a safe level that helps people improve their wellness, productivity,metabolism or comfort, improve performance of mental and/or physicaltasks, increase their alertness, quality of life and pleasure, reducetheir drowsiness, and aid in curing and preventing disease.

Oxygen sensors are well known in the art as disclosed by U.S. Pat. Nos.5,036,852 and 5,706,801, the disclosures of which are incorporatedherein by reference. Oxygen concentration sensors are commerciallyavailable. In preferred embodiments, the sensor can be optical,electrical or chemical.

The system further includes a regulator for controlling or regulatingthe flow of oxygen from the molecular sieve pressure cycle mechanismthrough the conduit into the enclosed space. The regulator receives themeasurement from the sensor and operates much like a thermostat toregulate oxygen flow. The regulator starts the flow of oxygen when thepercent oxygen concentration in the enclosed space falls to or below apre-selected percent, such as 21-23% by volume, preferably 21%, andstops the flow when the concentration rises to a preselected percentsuch as 35-40% by volume, preferably 40%. In additional embodiments, theoxygen concentration of the air in the enclosed space is maintained atany percentage between 21-40% oxygen by volume (i.e. 21%, 22%, 23% . . .up to and including 40%).

The oxygen sensor and regulator are also referred to herein as oxystat.In a preferred embodiment, the oxygen concentration percentage isdetermined, maintained and regulated by an oxystat. In anotherembodiment, the oxygen concentration sensor and regulator can maintainthe oxygen concentration of air in the enclosed space within a saferange. The safe range can be any percentage between 21-40% oxygen byvolume but not exceed 40% oxygen by volume.

The regulator can optionally regulate the flow of oxygen-enriched air tothe enclosed space either by switching the molecular sieve pressurecycle mechanism on and off or by operating a valve, which controls theoxygen-enriched air flow into the enclosed space. Computer controlledregulators for such purposes are well known in the art.

The system may further include an automatic shutoff system. Theautomatic shutoff system prevents oxygen from being directed to theenclosed space when the enclosed space is opened to ambient air or whena fire hazard is identified. The fire hazard that is identified can be asmoke detector, fire alarm, sprinkler system, infra-red sensing or othermeans of detecting fire. The system may also include a diluter, asdescribed below, for diluting the oxygen before it is fed throughconduit into the enclosed space.

For safety reasons, it is critical that the second pre-selected oxygencontent for shutting the molecular sieve pressure cycle mechanism off beat a safe level which does not create a risk of rapid combustion oflighted objects such as cigarettes or other combustibles that might beintentionally or accidentally ignited in the enclosed space. However,significant increases in wellness, productivity, metabolism or comfort,improved performance of mental and/or physical tasks, increasedalertness, quality of life and pleasure, reduced drowsiness, and aid incuring and preventing disease should result from small increases (suchas 2-15% increases) in the oxygen content in the enclosed. Such smallincreases are safely below an oxygen level that might be hazardous.

In a preferred embodiment, the molecular sieve pressure cycle mechanismis a pressure swing adsorption (PSA) apparatus, which moderatelyincreases oxygen concentration levels. The benefit of elevated oxygenconcentration in an enclosed space may only require moderate enhancementof ambient concentration (i.e. up to ˜40%).

PSA, with slight modifications, is a very attractive solution forenriching the ambient oxygen concentration. This system is similar inmany ways to air condition systems due to its low maintenance andmoderate energy consumption. Oxygen throughputs of most commerciallyavailable PSA systems today are modest, typically 3-100 liters of 95%pure oxygen per minute. In a preferred embodiment, the PSA apparatus, orother oxygen separator, can be used in combination with a supplementaloxygen source, i.e. oxygen battery, to allow rapid increase in oxygenconcentration. An oxygen battery can be used in vehicles or otherenclosed spaces that by their nature are not to be constantly enriched.The oxygen battery source allows rapid increase of oxygen concentrationto desired, safe levels when needed, without requiring very largeconstant throughput from the PSA apparatus, or other oxygen separator.In another embodiment, the oxygen battery is a refillable container thatis kept filled or charged by the PSA apparatus, or other oxygenproducer, when it is depleted. Therefore, in this embodiment, the PSAapparatus, or other oxygen producer, has dual role of supplyingoxygen-enriched air to the enclosed space, when in use, and rechargingthe oxygen battery when needed. In an additional embodiment, the systemmay also include an oxygen or automatic shunt which directs producedoxygen to the oxygen battery when the enclosed space is opened toambient air.

In a preferred embodiment, the system enriches the enclosed space withoxygen, such that said enriched enclosed space has elevated oxygencontent for a prolonged or extended period of time. A prolonged orextended time period means several consecutive hours or days. In apreferred embodiment, a prolonged or extended period of time means atleast three hours a day or at least four days a week. In anotherpreferred embodiment, a prolonged or extended period of time means atleast four days a week for three hours a day.

In a preferred embodiment, the present invention includes a method wheresupplying oxygen-enriched air to a enclosed space for a prolonged periodof time helps people improve their wellness, productivity, metabolism orcomfort, improve performance of mental and/or physical tasks, increasetheir alertness, quality of life and pleasure, reduce their drowsiness,and aid in curing and preventing disease.

Higher throughput on-site oxygen purification systems are also possibleas high flux is required only to initially charge the enclosed space,with much lower flux required subsequently to sustain an elevatedconcentration. The initial high flux could be delivered from the oxygenbattery (i.e. tank or container) that is constantly kept charged in thebackground, as described herein.

Traditional PSA based oxygen enrichment systems operate a regular cycleof highpressure and low-pressure steps, each of a particular duration.During each cycle most of the gas components of the air other thanoxygen are adsorbed onto a molecular sieve, after which the purifiedoxygen is extracted, and later the unwanted adsorbed gases are releasedas exhaust, at which point the system is ready for another cycle withnewly supplied air.

By shortening the amount of time allowed for adsorption, or changing thepressure or amount of gas introduced in each cycle, substantial amountsof nitrogen may remain unadsorbed, namely, still mixed with the freeoxygen when the latter is extracted. Although PSAs are seldom designedto operate that way (because there has been little use formoderatelyenriched O₂—N₂ mixtures until now), it is feasible andpotentially advantageous to do so, as it allows a shorter pressure cyclewith, in effect, higher throughput, or alternatively the use of asmaller molecular sieve to achieve the same throughput with lower costsor lower space requirements.

In a preferred embodiment the pressure swing adsorption system isdesigned to produce partially enriched air with oxygen concentration of22% to 75% by volume. In additional embodiments, the partial elevationof oxygen concentration allows higher throughput of enriched air ascompared with a similar system designed to produce purified oxygen. Thepartial concentration of oxygen is obtained by shortening the durationof the adsorption cycle whereby allowing only partial adsorption andremoval of the ambient nitrogen, by reducing the adsorption capacity ofthe molecular sieve, or by increasing the pressure differential duringthe cycle. The system is capable of easily changing its output gas toany desired level of oxygen concentration simply by changing the timingand duration of the pressure cycle. The system can be used to removecarbon dioxide, carbon monoxide and other unwanted gases from theenriched air without necessarily elevating its oxygen concentration.

The deployment of oxygen-enriched air can be accomplished byincorporating oxygen-enriched air flow into a central ventilationsystem, heating system, air conditioning system or other climate controlsystem. The flow can also be incorporated into a stand alone window unitor room unit. The system also incorporates an oxystat into thethermostats or control units. Therefore, it can be part of a feedbacksystem to control the desired oxygen concentration much like athermostat. It can be utilized for passive monitoring or activeregulation of oxygen levels. It can also be a part of multiple zoneswithin a residence or facility, if needed, much like heat or airconditioning. The multiple zones can be controlled within differenttarget ranges from a single source.

The oxygen supply system utilizing a PSA apparatus can be a closed loopsystem. The PSA supplying the oxygen-enriched air can receive some ofits oxygen feedstock from the target enclosed space. This avoidsdiscarding enriched air or over pressuring the enclosed space.Alternatively, the PSA can use the enclosed space feedstock incombination with additional external feedstock. This would guaranteepressure balance with the outside environment. This can also be used toflush out the molecular sieve during the desorption cycle.

A typical bedroom contains ˜50,000 liters of air and a moderate-sizedsingle family residence about ten times that amount. It would takeapproximately 10,000 liters of oxygen to double the concentration from20% to 40% in a single room. It would take several hours to bring asingle room to 40% with a 50 liter/min unit. It would take a day or twoto charge an entire house with 100,000 liters. In order to allow a quickramp-up or increase, a high pressure external oxygen battery (i.e.storage tank) can be kept charged at all times without the need for anexpensive high-throughput concentrator. For example, a standard uprightgas cylinder can store up to 10,000 liters.

Utilization of a PSA apparatus with oxygen-enrichment systems furtherallows the selective removal of pollutants and unwanted gases from theair as part of the oxygen enrichment cycle. Most gases are adsorbed inthe molecular sieve process so that oxygen-enriched air is very low inCO₂, humidity and pollutant gases like carbon monoxide (CO) and nitrousoxide (NOx) among others. This is particularly true if the PSA cycle isdesigned to produce moderate oxygen concentrations and high throughput,as described above, for it will replace most of the ambient air with airthat has been purified in this manner. Particularly beneficial in highlypolluted environments including, but not limited to; heavy traffic,industrial zones or dense urban areas. In another embodiment, thepressure swing adsorption apparatus selectively removes pollutants andunwanted gases from ambient air, such that purified oxygen-enriched airis produced.

In a preferred embodiment, the invention includes a method for supplyingoxygen-enriched air to a enclosed space to help people improve theirwellness, productivity, metabolism or comfort, improve performance ofmental and/or physical tasks, increase their alertness, quality of lifeand pleasure, reduce their drowsiness, and aid in curing and preventingdisease. The method includes the use of the PSA system described above.The method can increase the oxygen concentration of the air in thevehicle's enclosed space within a safe range, such as, about 21-40%oxygen by volume but not exceed 40% by volume.

In a preferred embodiment, the system described above can be used tosupply oxygen-enriched air to an enclosed space in a vehicle. The systemis similar to the oxygen-enrichment system described above. The systemcan include a PSA for producing the oxygen enriched air, a conduit orpipe for flowing the oxygen enriched air to the vehicle's enclosedspace, an oxygen battery, an oxygen concentration sensor for measuringoxygen content in the vehicle's enclosed space and an apparatus formaintaining the oxygen content in the vehicle's enclosed space within asafe range of 26-40% oxygen by volume. In another embodiment, the oxygencontent of the air in the vehicle's enclosed space is maintained at anypercentage between 26-40% oxygen by volume (i.e. 26%, 27%, 28% . . . upto and including 40%). The apparatus for determining and maintaining theoxygen content can be a oxystat or a sensor/regulator device. The oxygenbattery can rapidly increase the concentration in the vehicle's enclosedspace. The oxygen battery can be a refillable container which is filledby the PSA.

In a preferred embodiment, the PSA enriches said enclosed space withoxygen, such that said enriched enclosed space has elevated oxygencontent for a prolonged period of time. In a preferred embodiment, aprolonged or extended period of time means at least one hour a day. In apreferred embodiment, the oxygen concentration of the air in saidenclosed space is increased within a safe range of 26-40% oxygen byvolume for a long period of time.

The present invention also includes a method of supplyingoxygen-enriched air to a enclosed space for a prolonged period of timehelps people improve their wellness, productivity, metabolism orcomfort, improve performance of mental and/or physical tasks, increasetheir alertness, quality of life and pleasure, reduce their drowsiness,and aid in curing and preventing disease.

In additional embodiments, the PSA can include an automatic shutoffsystem, which prevents oxygen from being directed to the enclosed spacewhen the enclosed space is opened to ambient air, as by opening a dooror a window, or when a fire hazard is identified. The fire hazard can beidentified by a smoke detector, fire alarm, sprinkler system, infra-redsensing or other means of detecting fire. It can also include an oxygenshunt, which directs produced, oxygen to the oxygen battery when theenclosed space is opened to ambient air. The PSA may selectively removespollutants and unwanted gases from ambient air, such that purifiedoxygen-enriched air is produced. The PSA can be a closed loop system,where the closed loop PSA receives part of its oxygen feedstock from thevehicle's enclosed space for producing oxygen-enriched air for the sameenclosed space.

In a preferred embodiment, the conduit is incorporated into aventilation or climate control system for flowing the oxygen-enrichedair from the PSA into the vehicle's enclosed space.

In a preferred embodiment, the invention includes a method for supplyingoxygen-enriched air to a enclosed space in a vehicle to help peopleimprove their wellness, productivity, metabolism or comfort, improveperformance of mental and/or physical tasks, increase their alertness,quality of life and pleasure, reduce their drowsiness, and aid in curingand preventing disease. The method includes the use of the PSA systemdescribed above. The method can increase the oxygen concentration of theair in the vehicle's enclosed space within a safe range, such as, about26-40% oxygen by volume but not exceed 40% by volume.

Electrolyzer

In another embodiment, the oxygen generating system comprises anelectrolyzing unit, a container for water, a sensor and a regulator. Thesystem preferably uses deionized or distilled water to avoid or minimizebuild-up of scale and debris in the electrolyzer. Electrolyzing devicesare well known in the art as is disclosed in U.S. Pat. Nos. 5,037,518;5,589,052; and 5,690,797, the disclosures of which are incorporatedherein by reference. Such electrolyzing systems can generate high puritygases under pressure in a safe manner without need for gas compressors.Apparatuses for generating gaseous oxygen are commercially available.

The electrolyzer produces gaseous hydrogen, as well as oxygen. Thehydrogen gas may be used to power hydrogen fuel sells, an internalcombustion engine, or alternatively it can be exhausted to theatmosphere. The hydrogen gas is produced in relatively small quantities,and can be dispersed safely and easily into the ambient air. However,use of hydrogen, as a fuel supplement may be desirable.

The system further has a pipe or conduit device for flow of oxygen tothe enclosed space from the oxygen generator and a conduit for flow ofhydrogen to a fuel cell, engine or to an outside vent. The generation ofoxygen and hydrogen by the electrolyzer can produce sufficient gaspressure to move the gases through the conduits without need for acompressor, fan or other such device, but such flow-enhancing devicesare also anticipated for use in this invention.

The system works much like the system disclosed above to enrich theoxygen content of the air in an enclosed space to a safe level thathelps people improve their wellness, productivity and comfort, increasetheir alertness, quality of life and pleasure, reduce their drowsiness,and aid in curing and preventing disease and increased overallwell-being. The system preferably includes an oxygen sensor or othermeasuring device for sensing and measuring the oxygen content in the airin the enclosed space and further includes a regulator for controllingor regulating the flow of oxygen from the electrolyzer through theconduit into the enclosed space as described for the molecular sievepressure cycle mechanism above.

The system also preferably includes an oxygen dilution device fordiluting the concentration of the oxygen in the air that is fed into theenclosed space through the conduit. Diluter devices are well known inthe art as, for example, are disclosed by U.S. Pat. Nos. 3,875,957;4,036,253; 4,848,333; and 5,372,129, the disclosures of which areincorporated by reference. The dilution device reduces the concentrationof oxygen from approximately 100%, as it comes from the electrolyzer,down to approximately 40-50% oxygen, so it can be safety fed into theenclosed space. The diluter can use outside (fresh) air or recirculatedair from the enclosed space for mixing with the oxygen to dilute it.Dilution of the oxygen is desirable to reduce the possibility thathighly concentrated oxygen could be a fire hazard if it contactscombustibles in the enclosed space. It may also be desirable that theoutlet for feeding oxygen-enriched air into the enclosed space belocated such that the enriched air will not contact combustibles untilthe air is further diluted by air in the enclosed space. Such locationcould be, for example, within a ventilation duct, heating system, or airconditioning system.

Dilution of a gas stream containing 100% oxygen down to anoxygen-enriched air stream containing about 40-50% oxygen means that the100% oxygen is diluted with about 5-18 volumes of air depending on theoxygen content of the feed air and the desired oxygen content of theenriched air. If the feed air is outside air, it will have an oxygencontent of about 20% by volume, whereas recirculated air from theenclosed space might have up to about 35-40% oxygen content.

It may be desirable for the system to be limited to two settings for thedilution ratios, one when the oxygen is diluted by fresh air and theother when the oxygen is diluted by recirculated air so that the oxygencontent of the enriched air never exceeds a relatively low level such asabout 35-40% oxygen. Alternatively, the system may employ an oxygensensor that detects the percent oxygen in the enriched air and aregulator to control the amount of dilution to a predetermined safepercent. This offers the further advantage of increased effectivenesswhile minimizing risks of fire hazard. The dilution level could bemaintained at a level that would safely and quickly raise the oxygencontent in the enclosed space without need for excessive air flow. Ifthe enriched air has low oxygen content, such as about 40-50%, thenhigher air flow would be required to raise the oxygen content of the airin the enclosed space to a desired level of about 35-40% within areasonable period of time.

Oxygen Tank

In another embodiment, the present invention includes an oxygen supplysystem that uses oxygen from a tank(s) to deliver oxygen-enriched air toan enclosed space. The system includes a sensor for measuring the oxygencontent in the enclosed space, a regulator for opening and closing avalve and feeding oxygen into conduit, and a diluter for diluting theoxygen before it is fed through conduit into the enclosed space. Thetank or tanks may be located in a space adjoining the enclosed space orother space so that oxygen can be easily fed from the tank to theenclosed space. The system works much like the system disclosed above toenrich the oxygen content of the air in a enclosed space to a safe levelthat helps people increase their alertness, improve their productivityand comfort, reduce their drowsiness, and increase their overallwell-being. A tank is also referred to herein as a gas cylinder. Theseterms are utilized interchangeably. In a preferred embodiment, theoxygen tank is not the oxygen producing source but rather serves as theoxygen battery as described herein.

Membrane Filtration In another embodiment, the present inventionincludes an oxygen-enrichment system as described above that furtherincludes an oxygen-enrichment membrane to separate an oxygen-enrichedportion of ambient air, which is fed into an enclosed space. Membranesfor separating an oxygen-enriched component of gas are well known in theart. U.S. Pat. No. 5,709,732 discloses a variety of such membranes.Single and multiple stage membranes are known for producingoxygen-enriched gas. The membranes typically comprise hollow fibermembranes in bundles/modules. Ambient air is compressed and flows alongthe fiber bundle. A membrane can be selected that is more permeable tooxygen than to nitrogen, so an oxygen-enriched permeate gas and anitrogen-enriched retentate gas are produced. A single stage system willproduce modest increase in the permeate of up to about 30° O₂ dependingon the fibers. Additional stages may be used to produce more highlypurified oxygen. The disclosure of that patent and the references citedin the patent are incorporated herein by reference.

The system preferably includes a compressor for compressing ambient airthat is fed into the membrane to separate an oxygen-enriched permeategas and from a nitrogen-enriched retentate that is preferably exhaustedto the atmosphere. The permeate may desirably have an oxygen content ofabout 40-50%. As used herein “membrane” means a bundle or module ofhollow fibers that are more permeable to oxygen than to nitrogen. Thesystem also preferably includes a filter for filtering out dust andother solid impurities that could adversely affect the membrane. Thefilter may be of a variety of well known designs such as a typical airfilter for internal combustion engines or indoor ventilation systems.

The system may include a diluter such as that disclosed above. However,a diluter is not required if a membrane system is selected that producesoxygen-enriched permeate gas that is low enough in oxygen content thatit can be fed into the enclosed space without undue risk of undesirablecombustion in the compartment. Oxygen-enriched permeate having an oxygenconcentration of 40-50% may provide the desired enrichment of the air inthe enclosed space, provided the volume flow is at a reasonable level,without undue risk of accidental combustion.

The system may optionally include a sensor for measuring the oxygencontent of the air in the enclosed space as is described above and anassociated switch responsive to the sensor for switching the compressoron and off, depending on the oxygen concentration in the enclosed space.The sensor can be optical, electrical or chemical. The system may alsohave an on-off switch for manually switching the system on and off. Theswitch may be adjoining or located in the enclosed space.

One advantage of a membrane type system is that it may obviate any needto continuously measure the oxygen content of the air in the enclosedspace to regulate the system. Instead, a system can be provided thatproduces oxygen-enriched air containing approximately 40-50% oxygen insufficient quantities that the system will raise the oxygenconcentration in the enclosed space to the desired concentration withina relatively few minutes.

This approach is particularly attractive for automotive applicationswhere quick charging is of the essence and the volumes are much smaller.A typical vehicle enclosed space may have an air space of about 200 to600 cubic feet. A membrane type oxygen-enrichment system that has acapacity of producing approximately 100 to 300 or more cubic feet perminute (cfm) of oxygen-enriched air would quickly increase the oxygencontent of the air in the vehicle enclosed space to a desiredconcentration. The air flow capacity and oxygen-enrichment capacity of asystem could be matched with the size of a vehicle enclosed space tooperate the system continuously without risk of reaching excessiveoxygen concentration in the air in the vehicle enclosed space.

In another embodiment, the system includes a two-stage oxygen-enrichmentsystem for use in this invention. The two-stage oxygen-enrichment systemincludes two compressors and two air separation membranes for enrichingthe oxygen content of the air that is fed into enclosed space. Thistwo-stage system optionally includes an oxygen measuring sensor formeasuring the concentration of oxygen in the enclosed space andswitching one or both of the compressors on and off to regulate theconcentration of the oxygen in the enclosed space. The sensor can beoptical, electrical or chemical. The two-stage system may also include afilter for filtering out air-bone impurities from the ambient air thatis pulled into the compressor.

Cryogenic Separation Mechanism

In another embodiment, the present invention includes anoxygen-enrichment system as described above that further includes acryogenic separation mechanism to separate an oxygen-enriched portion ofambient air, which is fed into an enclosed space. The system includes asensor for measuring the oxygen content in the enclosed space, aregulator for opening and closing a valve and feeding oxygen intoconduit, and a diluter for diluting the oxygen before it is fed throughconduit into the enclosed space. This system works much like the systemdisclosed above to enrich the oxygen content of the air in a enclosedspace to a safe level that helps people increase their alertness,improve their productivity and comfort, reduce their drowsiness, andincrease their overall well-being.

Method of Producing Oxygen-Enriched Air

In a preferred embodiment, the present invention provides a method forsupplying a beneficial quantity of oxygen-enriched air to an enclosedspace in a safe and efficient manner utilizing any of the systemsdescribed herein. The method can significantly improve wellness,productivity, metabolism or comfort, improve performance of mentaland/or physical tasks, increase alertness, quality of life and pleasure,reduce drowsiness, and aid in curing and preventing disease.

The method of modified ambient oxygen level can be practiced in numerousenclosed spaces or compartments. It can be used in a residence, room,house, apartment, building, theater, shopping center, hotel, office,industrial facility, commercial facility, commercial venue, passengercar, truck, van, bus, tractor, ship, boat, submarine, aircraft, train orsubway car to help people improve their wellness, productivity,metabolism or comfort, improve performance of mental and/or physicaltasks, increase their alertness, quality of life and pleasure, reducetheir drowsiness, and aid in curing and preventing disease. This can beutilized by normally healthy individuals, in selected times and placesand for older or sick individuals with weakened physical ability.

Higher oxygen levels may be needed for peak health, vitality, immunesystem function, and longevity. Scientific evidence suggests that thehuman body is meant to function at far higher concentrations of oxygenthan it is currently getting, that the total dissolved oxygen content ofmost people's bodies today is considerably lower than what's needed tomaintain health, high energy levels and proper metabolism, and that thelower the dissolved oxygen content is in a person's body, the greaterthe body's susceptibility to chronic illness and disease.

It is possible that insufficient oxygen results in insufficientbiological energy that can further result in anything from mild fatigueto life threatening disease. Evidence suggests that a link betweeninsufficient oxygen and disease has been firmly established. Somesymptoms of oxygen deficiency include but are not limited to; overallbodily weakness, muscle aches, depression, dizziness, irritation,fatigue, memory loss, irrational behavior, chronic hostility,circulation problems, poor digestion, acid stomach, lowered immunity tocolds, flu and infections, bronchial problems, tumors and depositbuildups, bacterial, viral and parasitic infections. These symptomsoften begin with a vague feeling of uneasiness. They progress over time,to full-blown illness and disease.

Other Embodiments

Although particular embodiments have been disclosed herein in detail,this has been done by way of example for purposes of illustration only,and is not intended to be limiting with respect to the scope of theappended claims, which follow. In particular, it is contemplated by theinventors that various substitutions, alterations, and modifications maybe made to the invention without departing from the spirit and scope ofthe invention as defined by the claims. For example, a variety of otheroxygen generating systems or chemical reactions might be used togenerate oxygen for use in the invention. A variety of control systemscan also be used to regulate the oxygen content or flow rate of theenriched air that is fed into the enclosed space. Such control systemscould vary, for example, the electrical power that is provided to theelectrolyzing unit or to the compressors. Dampers could also be used toregulate the flow of oxygen-enriched air into the enclosed space in theseveral embodiments selected for illustration. The claims presented arerepresentative of the inventions disclosed herein. Other, unclaimedinventions are also contemplated. Applicants reserve the right to pursuesuch inventions in later claims.

What is claimed is:
 1. A system for supplying oxygen-enriched air to anenclosed space, said system comprising: means for producingoxygen-enriched air; a) a conduit for flowing said oxygen-enriched airinto said enclosed space; b) an oxygen concentration sensor formeasuring the oxygen content of air in said enclosed space; and c) meansfor maintaining the oxygen concentration of the air in said enclosedspace within a safe range.
 2. The system of claim 1, wherein said meansfor maintaining the oxygen content of the air in said enclosed spacecomprises a sensor for measuring the oxygen content of saidoxygen-enriched air and a regulator for regulating the flow ofoxygen-enriched air into said enclosed space to commence the flow ofoxygen when the oxygen content in said enclosed space falls below afirst pre-selected level and to stop the flow when the oxygen content insaid enclosed space rises above a second pre-selected level.
 3. Thesystem of claim 2, wherein said first pre-selected level is about 21%oxygen by volume.
 4. The system of claim 2, wherein said secondpre-selected level is about 40% oxygen by volume.
 5. The system of claim1, wherein said oxygen concentration of the air in said enclosed spaceis maintained at any percentage between 21-40% oxygen by volume.
 6. Thesystem of claim 5, wherein any percentage between 21-40% oxygen byvolume is determined and maintained by an oxystat.
 7. The system ofclaim 1, wherein said system further comprises an oxygen battery.
 8. Thesystem of claim 7, wherein said oxygen battery rapidly increases theoxygen concentration of an enclosed space within a safe range.
 9. Thesystem of claim 8, wherein said oxygen battery is a refillablecontainer.
 10. The system of claim 9, wherein said oxygen battery isfilled by said oxygen producing means.
 11. The system of claim 1,wherein said enclosed space is selected from the group consisting of:residence, room, house, apartment, building, theater, shopping center,hotel, office, industrial facility, commercial facility and commercialvenue.
 12. The system of claim 1, wherein said means for producingoxygen-enriched air comprises a molecular sieve pressure cyclemechanism.
 13. The system of claim 12, wherein said molecular sievepressure cycle mechanism is a pressure swing adsorption apparatus. 14.The system of claim 1, wherein said means for producing oxygen-enrichedair comprises a cryogenic separation mechanism.
 15. The system of claim1, wherein said means for producing oxygen-enriched air comprises anelectrolyzing device.
 16. The system of claim 1, wherein said means forproducing oxygen-enriched air comprises an oxygen tank.
 17. The systemof claim 1, wherein said means for producing oxygen-enriched aircomprises at least one gas separation membrane.
 18. The system of claim1, further comprising an oxygen shunt, wherein said shunt directsproduced oxygen to the oxygen battery when the enclosed space is openedto ambient air.
 19. A method for supplying oxygen-enriched air to aenclosed space, said method comprising the system of claim 1, whereinsaid method increases the oxygen concentration of the air in saidenclosed space within a safe range for a prolonged period of time. 20.The method of claim 19, wherein said prolonged period of time is anexposure of at least 3 hours per day, or at least 4 exposures per weekeach for a time of 3 hours.
 21. The method of claim 19, whereinsupplying oxygen-enriched air to a enclosed space for a prolonged periodof time helps people improve their wellness, productivity, metabolism orcomfort, improve performance of mental and/or physical tasks, increasetheir alertness, quality of life and pleasure, reduce their drowsiness,and aid in curing and preventing disease.
 22. A system for supplyingoxygen-enriched air to an enclosed space, said system comprising: a) apressure swing adsorption apparatus for producing oxygen-enriched air;b) a conduit for flowing said oxygen-enriched air from said apparatusinto said enclosed space; c) an oxygen concentration sensor formeasuring the oxygen content of air in said enclosed space; and d) meansfor maintaining the oxygen content of the air in said enclosed spacewithin a safe range.
 23. The system of claim 22, wherein said means formaintaining the oxygen content of the air in said enclosed spacecomprises a sensor for measuring the oxygen content of saidoxygen-enriched air and a regulator for regulating the flow ofoxygen-enriched air into said enclosed space to commence the flow ofoxygen when the oxygen content in said enclosed space falls below afirst pre-selected level and to stop the flow when the oxygen content insaid enclosed space rises above a second pre-selected level.
 24. Thesystem of claim 23, wherein said first pre-selected level is about 21%oxygen by volume.
 25. The system of claim 23, wherein said secondpre-selected level is about 40% oxygen by volume.
 26. The system ofclaim 22, wherein said oxygen concentration of the air in said enclosedspace is maintained at any percentage between 21-40% oxygen by volume.27. The system of claim 26, wherein any percentage between 21-40% oxygenby volume is determined and maintained by an oxystat.
 28. The system ofclaim 22, wherein said system further comprises an oxygen battery. 29.The system of claim 22, wherein said oxygen battery rapidly increasesthe oxygen concentration of an enclosed space within a safe range. 30.The system of claim 29, wherein said oxygen battery is a refillablecontainer.
 31. The system of claim 30, wherein said oxygen battery isfilled by said pressure swing adsorption apparatus.
 32. The system ofclaim 22, wherein said enclosed space is selected from the groupconsisting of residence, room, house, apartment, building, theater,shopping center, hotel, office, industrial facility, commercial facilityand commercial venue.
 33. The system of claim 22, further comprising anautomatic shutoff system, wherein said automatic shutoff system preventsoxygen from being directed to the enclosed space when the enclosed spaceis opened to ambient air or when a fire hazard is identified.
 34. Thesystem of claim 33, wherein said fire hazard is identified by a smokedetector, fire alarm, sprinkler system, infra-red sensing or other meansof detecting fire.
 35. The system of claim 22, further comprising anoxygen shunt, wherein said shunt directs produced oxygen to the oxygenbattery when the enclosed space is opened to ambient air.
 36. The systemof claim 22, wherein said pressure swing adsorption apparatusselectively removes pollutants and unwanted gases from ambient air, suchthat purified oxygen-enriched air is produced.
 37. The system of claim22, wherein said pressure swing adsorption apparatus is a closed loopsystem, such that said closed loop pressure swing adsorption apparatusreceives oxygen feedstock from said enclosed space for producingoxygen-enriched air for said enclosed space.
 38. The system of claim 22,wherein said conduit is incorporated into a ventilation or climatecontrol system for flowing said oxygen-enriched air from said apparatusinto said enclosed space.
 39. The system of claim 38, wherein saidventilation or climate control system is selected from the groupconsisting of central air-conditioning system, central heating system,central ventilation system, standalone window unit and stand alone roomunit.
 40. The system of claim 22, wherein said pressure swing adsorptionsystem is designed to produce partially enriched air with oxygenconcentration of 22% to 75% by volume.
 41. The system of claim 40,wherein said partial elevation of oxygen concentration allows higherthroughput of enriched air.
 42. The system of claim 40, wherein saidpartial concentration of oxygen is obtained by shortening the durationof the adsorption cycle.
 43. The system of claim 40, wherein saidpressure swing adsorption system is capable of easily changing itsoutput gas to any desired level of oxygen concentration simply bychanging the timing and duration of the pressure cycle.
 44. The systemof claim 40, wherein said partial concentration of oxygen is obtained byreducing the volume or capacity of the molecular sieve.
 45. The systemof claim 40, wherein said partial concentration of oxygen is obtained byincreasing the pressure differential during the cycle.
 46. The system ofclaim 40, wherein said pressure swing adsorption system removes carbondioxide, carbon monoxide and other unwanted gases from the enriched airwithout necessarily elevating its oxygen concentration.
 47. A method forsupplying oxygen-enriched air to a enclosed space, said methodcomprising the system of claim 22, wherein said method increases theoxygen concentration of the air in said enclosed space within a saferange for a prolonged period of time.
 48. The method of claim 47,wherein said prolonged period of time is an exposure of at least 3 hoursper day, or at least 4 exposures per week each for a time of 3 hours.49. The method of claim 47, wherein supplying oxygen-enriched air to aenclosed space for a prolonged period of time helps people improve theirwellness, productivity, metabolism or comfort, improve performance ofmental and/or physical tasks, increase their alertness, quality of lifeand pleasure, reduce their drowsiness, and aid in curing and preventingdisease.
 50. A system for supplying oxygen enriched air to an enclosedspace in a vehicle, said system comprising: a) a pressure swingadsorption apparatus for producing oxygen-enriched air; b) a conduit forflowing said oxygen-enriched air from said apparatus into said enclosedspace; c) an oxygen battery; d) an oxygen concentration sensor formeasuring the oxygen content of air in said enclosed space; and e) meansfor maintaining the oxygen content of the air in said enclosed spacewithin a safe range, wherein said safe range is 26-40% oxygen by volume.51. The system of claim 50, wherein said oxygen concentration of the airin said enclosed space is maintained at any percentage between 26-40%oxygen by volume.
 52. The system of claim 51, wherein any percentagebetween 26-40% oxygen by volume is determined and maintained by anoxystat.
 53. The system of claim 50, wherein said oxygen battery rapidlyincreases the oxygen concentration of an enclosed space within a saferange.
 54. The system of claim 53, wherein said oxygen battery is arefillable container.
 55. The system of claim 54, wherein said oxygenbattery is filled by said pressure swing adsorption apparatus.
 56. Thesystem of claim 50, wherein said vehicle is selected from the groupconsisting of passenger car, truck, van, bus, tractor, ship, boat,submarine, aircraft, train and subway car.
 57. The system of claim 50,further comprising an automatic shutoff system, wherein said automaticshutoff system prevents oxygen from being directed to the enclosed spacewhen the enclosed space is opened to ambient air or when a fire hazardis identified.
 58. The system of claim 57, wherein said fire hazard isidentified by a smoke detector, fire alarm, sprinkler system, infra-redsensing or other means of detecting fire.
 59. The system of claim 50,further comprising an oxygen shunt, wherein said shunt directs producedoxygen to the oxygen battery when the enclosed space is opened toambient air.
 60. The system of claim 50, wherein said pressure swingadsorption apparatus selectively removes pollutants and unwanted gasesfrom ambient air, such that purified oxygen-enriched air is produced.61. The system of claim 50, wherein said pressure swing adsorptionapparatus is a closed loop system, such that said closed loop pressureswing adsorption apparatus receives oxygen feedstock from said enclosedspace for producing oxygen-enriched air for said enclosed space.
 62. Thesystem of claim 50, wherein said conduit is incorporated into aventilation or climate control system for flowing said oxygen-enrichedair from said apparatus into said enclosed space.
 63. A method forsupplying oxygen-enriched air to a enclosed space in a vehicle, saidmethod comprising the system of claim 50, wherein said method increasesthe oxygen concentration of the air in said enclosed space within a saferange for a long period of time, wherein said safe range is 26-40%oxygen by volume.
 64. The method of claim 63, wherein said prolongedperiod of time is an exposure of at least 1 hour per day.
 65. The methodof claim 63, wherein supplying oxygen-enriched air to a enclosed spacefor a prolonged period of time helps people improve their wellness,productivity, metabolism or comfort, improve performance of mentaland/or physical tasks, increase their alertness, quality of life andpleasure, reduce their drowsiness, and aid in curing and preventingdisease.